Nitroglycerin combination hook



Dec. 12, 1939. w. A. THORNTON NITROGLYCERIN COMBINATIUN HOOK Filed July25, 1938 "HUI afimwm w Patented Dec. 12, 1939 UNITED STATES PATENT FFIE NITROGLYCERIN COMBINATION HOOK Word Augustus Thornton, Amarillo, Tex

Application July 25, 1938, Serial No. 221,271

6 Claims.

My invention relates to an improvement in nitroglycerin combination hooks.

The object is to provide means for lowering and releasing a torpedo with comparative safety to the operator by making provision against premature release and explosion.

Another object is to provide a safety hook of such construction that the torpedo can be lowered to the bottom of a well of any known depth without danger of accidental or premature release and finally released by the operator from his position at the top of the well by his exercise of a predetermined number of successive upward jerks on the lowering cable.

With these and other objects in view, my invention consists of an outer shell which may, for convenience, be made in two parts screwed securely together and housing a spring-pressed slidable plunger having a spring-pawl. The lower end of the lower section of the shell having an upwardly opening hook, the opening of which is controlled by a notched rotatable wheel which is actuated step by step, to turn a notch at a time, in response to the successive upward jerks of the cable to open the hook for the release of the bail of the torpedo, when the predetermined number of jerks have been completed. A second spring pawl holds the rotary wheel while the actuating spring pawl takes another hold. A spring pressing down onthe plunger with each slackening of the cable causes a downward movement of the encased plunger. This action is repeated until the operator knows by the count of the notches passed that the hook is opened, whereupon a slight further lowering of the cable permits the hook to drop from the torpedo bail and become released.

In the accompanying drawing:

Fig. l is a longitudinal section;

Fig. 2 is a similar section taken at right-angles to Fig. 1; and

Fig. 3 is an irregular horizontal section on line 3-3 of Fig. 1, looking upward in the direction of the arrows.

The sections of the outer casing are represented by numerals l and 2. The lower section is made in two parts as shown in Fig. 2, and these are held together by pins 3 just below the hook 4 and at the upper end by the section I of the casing screwed thereon by threads 5 provided for that purpose.

A plunger 6 is fitted within the casing where it is slidably confined for limited up and down movement and is backed by a moderately stiff spring 7 which exerts pressure on the plunger to normally force it downward. The spring-pawl 8,

which is secured to the plunger 6, is lowered successively with each lowering of the cable preparatory to a pull upwardly, into one notch 9 after another of the notched rotatable wheel l0, which wheel turns on its bearing pin II.

The secondary locking spring pawl l2 holds the wheel ltl until the primary spring-pawl 8 enters another notch 9 to take a new hold and impart another slight turn to the wheel ll). There are preferably ten notches to be engaged by the spring-pawl 8, and consequently ten drops and upward pulls on the cable bring the flat portion E3 on the wheel ill in line with an edge of the hook 4, opening the latter so the book may be lowered from the bail of the torpedo and released therefrom.

A pin M is attached to the plunger 6 and an eye i5 on its upper end is provided for the attachment of the cable (not shown).

A keyhole It is provided in one end of the pin H to receive a key (not shown) for turning and adjusting the wheel Ill to a position across the hook to hold the bail of the torpedo therein, and the secondary spring-pawl l2 holds it locked in the position to which it is manually turned.

The release is simple and predetermined by successive jogging of the cable up and down upon the hook the ten, or required number, of times so that the action is with precision and safety.

I claim:

1. A nitroglycerin hook including a casing, a movable plunger carrying a spring pawl engaging a notched wheel, said notched wheel normally closing the hook and rotatably supported in position to open the hook when moved by the plunger and pawl.

2. A nitroglycerin hook including a casing, a movable plunger carrying a spring pawl engaging a notched wheel, said notched wheel normally closing the hook and rotatably supported in position to open the hook when moved by the plunger and pawl, and a secondary spring pawl in position to lock the wheel.

3. A nitroglycerin hook including a casing, a spring-pressed movable plunger carrying a spring pawl engaging a notched wheel, said notched wheel rotatably supported in position to close the hook until rotated by the plunger and pawl, the plunger having means for the attachment of a cable.

4. A nitroglycerin hook including a casing, made in two sections screwed together, one section made of two parts, a notched wheel, having a segment removed therefrom, rotatable in a recess formed between these parts, a movable may be manually turned and set to its normal closing position.

6. Anitroglycerin hook consisting of a casing, a plunger movably supported therein, a wheel rotatably supported in the casing, a segment removed from one side of said wheel and notches on a portion of the remaining segment of the wheel, said Wheel normally closing the hook, and pawl means carried by the plunger for rotating the wheel sufiiciently to align the chord of the wheel 10 with the hook to open the latter.

WORD AUGUSTUS THORNTON. 

